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Hard-braking events as indicators of road segment crash risk

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Re: Hard-braking events as indicators of road segment crash risk

#471

Post by bluGill »

lazide wrote: post #441
direwolf20 wrote: post #433

Earlier quoted context omitted.

You mean 20 people who were trying to merge finally get to merge because someone came past who wasn't a massive asshole?

That person then gets screwed. Screwed person: WTF? People doing the screwing: ‘oh thank god’ The really irritating part - society saying ‘oh, that’s not happening you should continue to be screwed’

Nobody is getting screwed. I've been the person making the gap many many times. You just ignore them, it isn't hard - they are way up there and I'm way back here, plenty of space. I just keep on with my business of safely driving. Sure I often wish I could go the speed limit - but in reality I'm going almost as fast as they are so it isn't like a few feet lost costs me anything. Odds are I'll be stopped at a red light and lose a lot more time once I get off the highway.

Besides, there are only a few people who ever merge in front of me (and then those who don't merge block their lane so nobody else can get in).

Re: Hard-braking events as indicators of road segment crash risk

#472

Post by [deleted] »

fransje26 wrote: post #428
CGMthrowaway wrote: post #365

Earlier quoted context omitted.

Of course braking/change in velocity creates waves. But this effect is overemphasized in my opinion. Locally analyzed, traffic can be simplified incredibly by observing that a lane's maximum throughput is simply given by following spacing, measured in time. If drivers are using a 2 second following distance, commonly taught in driving school, then max throughput is simply 1 car / 2 sec If you double following distanc…

> If you double following distance, you halve the throughput. If you halve following distance, you double your throughput. That postulate breaks down as soon as you move away from a laminar traffic assumption and include distracted drivers, lane changes, and weather influences. Which is why the wave theory model is important to understand the propagation of perturbations and their effect on maximum throughput. > The…

[deleted]

Re: Hard-braking events as indicators of road segment crash risk

#473

Post by anbotero »

closewith wrote: post #444
taneq wrote: post #408

Earlier quoted context omitted.

The issue is that when you slow down, you’re (a) creating ‘turbulence’ in the traffic flow with increased speed differential between cars and increased lane changes, which increases accident risk for everybody, and (b) it’s not even solving the problem because you still perpetually have some impatient driver wedging themself in directly in front of you, deleting your buffer zone. It’s safer to drive a little closer,…

> The issue is that when you slow down, you’re (a) creating ‘turbulence’ in the traffic flow with increased speed differential between cars and increased lane changes, which increases accident risk for everybody, and (b) it’s not even solving the problem because you still perpetually have some impatient driver wedging themself in directly in front of you, deleting your buffer zone. That's very obviously not true. Slo…

Is there a statistics name for the last part? I'd like to compare different countries. It's definitely NOT true in Colombia at least, which makes me believe OP more.

We in Colombia had a public service announcement where it showed someone driving really fast (while still respecting semaphores), and another one going with just enough speed. In the end, they both reach the last semaphore almost at the same time and then they part ways. Essentially it shows that driving crazy fast in the city doesn't necessarily gets you faster to your destination.

Now that I'm an adult, I tested it several times, and it matches 90% of my attempts, but that's in the city, with semaphores. No way I'd think letting everybody steal everybody else's buffer would provide for a reduction in journey time, even in highways. You're adding items to a queue, it'll take longer.

Now, it is probably safer, but we can only take so much even if we are not in a rush.

Re: Hard-braking events as indicators of road segment crash risk

#474

Post by spacecadet »

Defensive driving. Two hands, eyes on the "road", not caring about fools and maintaining safe distances. You have all the time in the world... I Recommend taking your car to a HPDE event, sometimes insurance will discount you for this. In this case, hard braking, is you just not knowing anything about your car or the cars around you... I barely use my brakes, but I also drive manual... Id say learn engine braking but y'all probably driving those stupid over powered electric cars...

Re: Hard-braking events as indicators of road segment crash risk

#475

Post by albumen »

closewith wrote: post #446
HPsquared wrote: post #403

Earlier quoted context omitted.

Confusingly, the slow lane is called the "inside lane" in the UK, even though it's on the edge of the road and the fast lanes are in the middle.

That used to be the case in Ireland too, but confusion due to cultural contamination means pretty much everyone moved to numbering lanes (from the "outside"/"slow"/leftmost lane).

I've been driving in Ireland for 30 years and I've never heard anyone number lanes. For me it's left/slow; middle; or right/fast lane.

Re: Hard-braking events as indicators of road segment crash risk

#476

Post by stronglikedan »

Sohcahtoa82 wrote: post #213
mountain_peak wrote: post #46

Earlier quoted context omitted.

Maintaining a safe following distance is incredibly challenging on busy freeways where hard braking is often 'required'. Most people have likely found themselves in this situation: vehicle changes lanes in front of you; you slow down to maintain a safe following distance, another car sees a gap and changes lanes in front of you. Repeat for your entire commute. Incredibly frustrating, and I've driven all over North Am…

> vehicle changes lanes in front of you; I will never understand why this is so rage-inducing for people. Changing lanes is a necessary part of navigating, even during busy traffic. People on an on-ramp will need to get in front of somebody . People needing to move back to the right because their exist is coming up will need to get in front of somebody . Your lane is not a birth right. Let people merge. > you slow do…

You know very well that normal lane changing isn't what the person you're replying to is referring to.

Re: Hard-braking events as indicators of road segment crash risk

#477

Post by tsoukase »

techterrier wrote: post #386
tsoukase wrote: post #380

Earlier quoted context omitted.

Inter-car distance is always a safety factor but can immensely reduce lane throughput. There is a compromise. I remember a few decades ago, in California at least, they suggested the drivers keep a one-car length distance from the leading car for every 10m/h speed. Funny that I had to convert it in km/h.

not dying >>>>>> lane throughput

I am sure this rule of thumb was suggested after thoughtful weighing of traffic accident risk and jams in Cali's 8-lane highways. Everything is a compromise, often versus life.

Re: Hard-braking events as indicators of road segment crash risk

#478

Post by bluGill »

rramadass wrote: post #416
rramadass wrote: post #258

Earlier quoted context omitted.

> Driving is a fascinating ritual with vastly differing norms across regions. It would be interesting to learn if anthropologists have studied this And Psychologists! Reading the comments in this thread is quite amusing. As a driver in India, i can tell you anything goes as long as you don't get into an accident (which may/may-not kill you) or get caught by the police. No rules matter and the only goal is to "one-up"…

Addendum: Drive in India and you will understand mathematical concepts of Chance/Randomness/Probability/Non-determinism/Game Theory/etc. along with philosophical concepts of Fate/Destiny/Providence/etc. in so direct and visceral a manner that you will never forget the lessons. Sissified countries with rules and regulations for driving can never give you such direct knowledge. Game Theory - https://en.wikipedia.org/wi…

India is working to fix that. It is slow going, but things have improved over time, and police are enforcing driving laws (at least in some areas)

Re: Hard-braking events as indicators of road segment crash risk

#479

Post by notatoad »

4gotunameagain wrote: post #466
sagarm wrote: post #448

Earlier quoted context omitted.

They are making this data publicly available -- after aggregation and anonymization.

A fraction of the data they collect, to keep up appearances.

Publicly releasing 100% of the maps data they collect would be the most gigantic privacy violation the world has ever seen.

Re: Hard-braking events as indicators of road segment crash risk

#480

Post by lazide »

bluGill wrote: post #471
lazide wrote: post #441

Earlier quoted context omitted.

That person then gets screwed. Screwed person: WTF? People doing the screwing: ‘oh thank god’ The really irritating part - society saying ‘oh, that’s not happening you should continue to be screwed’

Nobody is getting screwed. I've been the person making the gap many many times. You just ignore them, it isn't hard - they are way up there and I'm way back here, plenty of space. I just keep on with my business of safely driving. Sure I often wish I could go the speed limit - but in reality I'm going almost as fast as they are so it isn't like a few feet lost costs me anything. Odds are I'll be stopped at a red ligh…

In high traffic you’re definitely being screwed - both by the continuing lack of a proper safety gap, and by not being able to go a normal speed. Which does add up in many of these situations.

But I guess we should just all self gaslight to feel better about it?

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